Reclosable plastic bags are used for many purposes, including as biohazard specimen bags for secondary specimen containment in hospitals and laboratories, for storing forensic evidence in law enforcement, and for storing and transporting food and other materials. Reclosable bags are often preferred over other available bags because of numerous advantages, including that they are spill resistant, easy to fill and close, and easy to reopen for access without compromise of integrity when closed.
In the laboratory or hospital setting, a collected specimen of blood, urine, or other biological fluid or tissue is typically first placed in a primary container, such as a tube, vial, or other suitable container, which is then sealed in a biohazard specimen bag for secondary containment, handling, and, if desired, identification. When filled with a specimen, the reclosable biohazard specimen bag is typically sent to a destination remote from the point of collection, such as a pathology laboratory for testing or examination of the specimen.
Conventional biohazard specimen bags typically comprise a reclosable plastic bag with a zip-action, locking reclosable closure that reduces the likelihood of inadvertent compromise or opening, such as from pressure created by changes in the contents. Because of the locking nature of the two interlocking parts or elements of the closure profile, the bag typically will open only if the laboratory worker firmly grasps with both hands the lips of the reclosable bag, created above the reclosable closure means, and pulls them apart in opposite directions using both hands.
There is presently a heightened sensitivity to the protection of laboratory workers, especially in light of the recent identification of numerous viral pathogens for which there presently are no known cure, e.g. HIV, HSV, and Ebola. These concerns have generated many rules and regulations regarding the procedures that testing laboratories must follow in handling biospecimens. Typically, a laboratory worker, often a pathologist or laboratory technician, is required to wear latex or other suitable protective gloves when handling a biohazard specimen bag and/or its contents, as protection against possible infectious agents or pathogens, such as bacteria or virus. The use of protective gloves often presents difficulty in opening the closure of a reclosable bag. Often, gloved persons have difficulty manipulating the bag to grasp the lips above the reclosable closure to permit opening the bag. Also, forceful pulling of the bag's lips may cause sudden opening of the bag and/or tearing along the sides of the bag. As a result, the contents may fall out of the bag, often breaking or damaging the integrity of the primary container, and potentially resulting in contamination of the specimen and/or the laboratory, and attendant risk to laboratory workers.
Because of the difficulty in opening a bag's reclosable closure, and the fact that the bag will likely not be reused in any event, many laboratory workers do not bother opening the reclosable closure. Instead, they may cut the bag to reach its contents. While cutting the bag facilitates reaching the bag's contents, the use of a blade presents another opportunity for health hazards and contamination. The laboratory worker may cut, puncture or injure a hand or finger in the process of cutting the bag; and/or the cutting blade may present a source of cross-contamination between specimens. Perforated bags could permit tearing the bag along a perforation through the bag without opening the reclosable closure means, but perforations are unacceptable or prohibited for many containment purposes, as the presence of perforations can permit air to enter the bag and might also allow contents to spill or leak from the bag. Perforated bags also can permit tampering with the bag's contents more readily than non-perforated bags, as the perforations can present potential paths of access to the bag's interior without substantial visual damage or alteration to the bag. Because of their decreased structural integrity, perforated bags generally are not well-suited for containing biohazardous materials.
In order to insure the integrity of the contents of a reclosable bag, it has been found desirable in many applications that the bags be provided with a tamper evident closure means. For example, forensic evidence can be collected at a crime scene, sealed in a reclosable bag, and stored until needed for laboratory analysis and/or use at trial. In order to later verify that the evidence analyzed by the laboratory or used at trial was the same evidence collected at the crime scene, and was unadulterated prior to its analysis or use at trial, tamper evident closure means are secured and a chain of custody is maintained. Tamper evident closure means are also desirable in other applications, such as secondary containment for the storage and transport of biologic and other materials to be subjected to laboratory analysis at a location remote from the point of collection, to insure that the contents are not contaminated or altered prior to analysis. Tamper evident closures are also advantageous in the storage and transport of food and other products to assist in verification of the container's integrity. Perforations in a tamper evident storage bag are particularly undesirable, as perforations present a pathway for inadvertent contamination or purposeful adulteration of the contents without readily observed alteration of the bag or its tamper evident features.
Thus it can be seen that a need exists for a non-perforated, reclosable bag that permits access to the contents of the bag without the need for opening the reclosable closure means, permitting ease of access, for example, by a person wearing gloves. A further need exists for a bag that provides a tamper-evident closure. It is to the provision of a bag meeting these and other needs that the present invention is primarily directed.